Process for the purification and decontamination of tertiary aliphatic amine solvents



Oct. 15, 1968 A. BATHELLIER ETAL ,2

PROCESS FOR THE PURIFICATION AND DECONTAMINATION OF TERTIARY ALIPHATIC AMINE SOLVENTS Filed Aug. 17, 1965 IN VENTORS flmae 54 THELL/EE JEAN-7260055 PEREZ ATTORNEYS United States Patent Ofice 3,406,204 Patented Oct. 15, 1968 3 406 204 PROCESS FOR THE PUl IFICAT ION AND DE- CONTAMINATION OF TERTIARY ALIPHATIC AMIN E SOLVENTS canting the activated earth in order to recover the purified solvent.

This process, aside from the fact that it is economically advantageous, does not exhibit any appreciable sensi- Andr Bathellier, Sceaux, and Jean-Jacques Perez, 5 tiVitY t moisture-laden and Permits a larger capacity Maisonsiilfort, ljrance, assignors to Commissariat to be processed and consequently a saving in time. Since alEnle rlglleiit0mi%ue1,9lzgng, Frlaice480 326 this process can be carried out in large containers instead 1 of alumina-packed columns the technology is according- Clams pnomy g g g g 1964 1y simplified to a considerable degree.

Claims. 260 583) 10 The activated natural earths employed are complex silico-aluminates which are prepared by acid activation of colloidal clays of smectic nature such as bentonites.

ABSTRACT OF THE DISCLOSURE This activation endows said complex silico-aluminates with enhanced adsorption properties.

This invention relates to a process for the purificafion In short, it can be stated that the adsorption process and decontamination of organic solvents constituted by results from the action of Van der Waals forces which ternary ammes' are developed between the molecules of adsorbable impurities and the active surface of the adsorbent. Under Background of the invention predetermined conditions of temperature and agitation, the impurities which are concentrated in the vicinity of The process generally comprises contacting the amine a e 22222312212552313552 ii ti isi iiirfiiiy imiiii ureo rom to oraperio 0 mm to minutes. The amount of activated alumino-silicate used gigg g ig gg f i g i j; 22 1; g f z iz ggi f i reprgsents about 3 to 10% by weight of 25 amine by virtue of its N-H li rikage is carried out selec t e so vent to e processe tivel The tert ar amine, on the other hand, is fixed onl Tnlaurylamlile dpdecolc acld sohmon 1s .Wldely as a result of induced polarity with the result that it ployed as an industrlal solvent for the purification of adsor tion is considerabl lowr plutonium in a nitric acid solution. However, this solvent 5 processing conditigns p first on the nature Loses a of ghemlcal punty dunng use and therefore of the activated earth and on a certain number of paramas to e pun e eters amon which can be mentioned the tern rature,

Thepunficatlon 9 9 generally cpmpnses an processing fime and percentage of activated e r th emextraction of the nitric acid complex of this metal folployed E by a g p g g i i Among the activated earths which are suitable for the tron y means 0 a mmera ase. e so vent w 1c is rac-tical a llcation of thls inventlon there can be clted ref'extracted.then agpezirs m the of a siolchlomemc by way of e xample the activated earths known as Clarsil nitrate of trilauramine ll'l. dodecoic acid solution. A regen- Pcl LE1 LE2 or Actisil T TS advanta eons use eration i the amine in the form free base y a mixtur? can also be made of mixtuies (if these activatid earths of Soda and carbqnate 1s i cariled i' with active carbons such as Acticarbone S, 28 or Negrisil laurylamine (TLA) conteims as pnnclpa} lmpurmes 40 21291 These active carbons serve to complete the aclaurylamine (DLA) and 1ts laureate which are troubletion of'the earths in two Wa S as follows some on account of their low solubility in dodecoic acid (a) By discoloring the Zolvent phase. The laurate of DLA can also produce during the basic regeneration emulsions of the collodial type which 32 fi' g ggii gfig z g i jg gg g sgg gg 2 the decantatlon of these sohmons dlfficult to perprocess which results in the final production of the DLA Up to the present time, the removal of DLA was carlaurate' ried out by passing the solvent mixture through an alumi- Tabfle I below Summanzes the results obtamed wlth na-packed column. However t hi s method is fairly costly, h dlflerent oactlvated earths p y f tests were has a certain degree of sensitivity to moisture-laden air out at 25 Over a Peflod 0f 30 {nll'lutes Wlth a q and finally does not permit of rapid processing of large W of earth equal t0 10% y Welght 0f the Solvent quantities of solvent. processed.

TABLE I Percent by Processing Nature of TLA-l-D LA TLA in DLA in weight of yield DLA, Loss TLA, Sample No. activated in moles per moles per moles per DLA with percent percent earth liter 'ter llter trespiog removed 1 Untreated 0.3030 0.2777 0.0253 6.19

. LE 0. 2750 0. 2662 0. 0088 2. 24 64 4. 1 0. 2700 0. 2638 0. 0062 1. 74 5. 0 0. 2670 0. 2617 0. 0053 1. 37 7s 5. s 0. 2680 0. 2631 0. 0049 1. 26 80 5. 3 0. 2690 0. 2645 0. 0045 1. 15 81 t 8 0. 2690 0. 2645 0. 0045 1. 15 81 4. s 0. 2650 0. 2609 0. 0041 1. 06 83 6. 0 0. 2620 0. 2596 o. 0024 0 63 00 6. 5

The present invention circumvents the disadvantages referred-to. The invention has for its object a method of purification of tertiary amin which consists in contacting the amine to be purified with an activated natural earth at a sufiiciently high temperature and over a suificient period of time to purity and decontaminate it, and in de- It is apparent from the results which have been tabulated above that the earths known as Actisil T, TS and TSL have better specificity with respect to DLA. Actisil TSL is of the same quality as Actisil TS but has a smaller particle size, and this property is liable to result in certain disadvantages, especially at the time of decantation.

In the case of the mixtures T+S and T+2S, the results obtained in the removal of DLA are of the same order as those obtained when employed the earths alone. However, as has been mentioned earlier, there is additionally obtaind complete discoloration of the solvent as well as removal of the oxide of TLA.

The influence of temperature has been determined by using an activated earth Actisil TSL in a quantity corresponding to 10% by weight of the solvent to be processed and by contacting continuously over a period of 45 minutes. Tests have shown that maximum processing efiiciency was obtained in respect of a temperature within the range of 40 to 50 C.

The influence of the processing time on its efficiency has been analyzed by employing a percentage of earths corresponding to 20% by weight of the solvent to be processed and by contacting at a temperature of 48 C. Tests carried out have shown that the process was efiicient for a length of time comprised between and 50 minutes and perferably in the vicinity of minutes. The loss of adsorbed TLA remains practically constant after a processing time of 10 minutes; said TLA is readily recovered by washing the activated earth with dodecane, for example.

However, the activated earth can first be contacted with a small quantity of pure solvent if so desired.

The efficiency of removal of DLA is in no way impaired by such a preliminary treatment.

The influence of the percentage of activated earths employed is highly important and has been studied in the case of different activated earths at a temperature in the vicinity of 45 C. and over a period of time varying between 10 and 45 minutes. The results obtained have shown that a percentage of earths within the range of 3 to 10% by weight of the solvent to be processed permits of sufiicient purification of DLA without entailing too substantial losses of TLA by adsorption.

The mean values of the results obtained by treating TLA with an activated earth such as Actisil TS at a temperature in the vicinity of 45 C. with contacting times ranging from 10 to 45 minutes and using ditferent percentages of activated earth are recorded in Table II below:

In addition to the purification of TLA, treatment by means of activated earths makes it possible to reduce to a substantial degree the settling time of the solvent in the presence of aqueous phases. Moreover, this treatment makes it possible to improve the decontamination factor of TLA with respect to the fission products and especially with respect to zirconium, niobium and ruthenium. In fact, a few fission products which include zirconium, niobium and ruthenium can be extracted from TLA.

A first decontamination of the solvent is carried out at the time of regeneration in the form of free base in the presence of a mineral base; the second decontamination is obtained at the time of the purification treatment with activated earths. By way of indication, approximately 85 to 90% of the residual activity of the solvent are thus fixed by the activated earth Actisil TS which is employed in a proportion of 5% by weight of the solvent to be processed. By way of example, 1 liter of trilaurylamine of concentration in dodecane derived from the final stage of purification of plutonium has been treated with 5% by weight of the activated earth Actisil TS for a period of 10 minutes at a temperature of C. The decontamination factors obtained in the case of the pair Zr Nb and the case of the pair Ru Rh were respectively 5 and 5.75.

The process according to the invention is of a general application. It allows to eliminate from solvents, impurities which are more polar than the solvent itself. If it can be used for example for the purification of tributylphosphate, it will be however preferable to apply the process of purification by carbonates which has the advantages of the liquid-liquide extraction process.

It can be applied to the purification of all tertiary amins. In this way the tricaprylylamine commercialized under the designation Alamine 333 has been purified in handling it during 4. hr. by a temperature of 45 C. with 10% in weight of activated earth Actisil TS. The dicaprylylamine contained in the amin has been completely eliminated.

The treatment is carried out by means of any conventional apparatus and especially by means of the apparatus shown in the single figure annexed hereto.

The apparatus comprises a mixer 2 surrounded by a heating jacket 3 fitted with conventional heating means such as an electric resistance 5. Said mixer is supplied with activated earth by means of a pipe 4 connected to a distributor which is not shown in the figure and is fitted with an inlet tube 6 for the admission of solvent to be processed as well as with a stirrer 8 for the purpose of ensuring good contact between the activated earth and the solvent to be purified.

Said mixer 2 is also provided with an outlet tube 10 fitted with a valve 11 for draining-01f the mixer and located at the bottom of this latter. Provision is made at the top of the mixer for an outlet tube 12 for the overflow discharge of processed solvent which is thus conveyed towards a settling column 14 in which the separation of the purified solvent from the spent activated earth is carried out.

There is located at the top end of the column 14 an outlet tube 16 for the discharge of decanted solvent and at the bottom end of the column a tube 18 fitted with a valve 19 for removing the sludges which consist of a mixture of solvent and spent activated earths.

The operation of this plant is apparent from the foregoing description and will therefore be described only briefly.

The mixer 2 is fed in a continuous manner with a tertiary amin by means of the tube 6 and is also Supplied with activated earths in a continuous manner by means of the tube 4. The activated earth distributor is regulated in such a manner as to introduce a predetermined percentage by weight of activated earths and the heating of the mixer jacket 3 is regulated in such a manner as to maintain a temperaure in the vicinity of 45 C. within the mixer.

After a predetermined period of time which is preferably of the order of 10 minutes, the processed solvent and the earth in suspension are discharged from the mixer 2 through the overflow 12 and are directed towards the settling column 14 which carries out the separation of the solvent from the earth.

The decanted and purified solvent passes out through the overflow 16 and the sludge is discharged through the tube 18 towards a filter system of conventional type which is not shown in the figure and which effects the separation of the earth; the filtered solvent is recovered.

This apparatus for the practical application of the process according to the invention has been described solely by way of non-limitative example. It would equally be possible to employ any conventional equipment which permits of an effective solid-liquid contact followed by the decantation of the aggregate for the purpose of recovering the purified liquid.

What we claim is:

1. A process for the purification and decontamination of a teriiary aliphatic amine solvent which comprises contacting said solvent with an activated silico-aluminate prepared by acid activation of colloidal clay, said silicoaluminate being used in an amount which constitutes from about 3 to 10% by weight of said solvent to be purified (b) the silico-aluminate is used in an amount repreand said contacting being carried out for from 5 to 50 enting about 10% by Weight of said solvent; and minutes at a temperature of from about 40 to 50 C. the contacting is Performed at about Q for 2. A process according to claim 1 wherein said tertiary about 30 minutesamine is trilaurylamine. 5

3. A process according to claim 1 wherein said tertiary References Clted amine is tricaprylylamine. UNITED STATES PATENTS 4. A process according to claim 1 wherein said activated 3 005 326 10/19 1 l k et 1 0 5 X silico-aluminate is mixed with activated carbon.

5. A process according to claim 1 wherein: 10 CHARLES B. PARKER, Primary Examiner.

(a) the mine is rilwylamine; R. L. RAYMOND, Assistant Examiner. 

